A more complicated flow comprising the wake interactions between two side-by-side uneven circular cylinders is also considered to
discuss the boundary of inter/extrapolation for training data.
A schematic view of the problem setup is shown in figure REF .
The two circular cylinders with a size ratio of \(r\)  are separated with a gap of \(gD\) , where \(g\)  is the gap ratio.
The Reynolds number is fixed at \(Re_D=U_{\infty }D/\nu =100\) .
The two cylinders are placed \(20D\)  downstream of the inlet where a uniform flow with velocity \(U_{\infty }\)  is prescribed, and \(40D\)  upstream of the outlet with zero pressure.
The side boundaries are specified as slip and are \(40D\)  apart.
The flows over the two cylinders are solved by the open-source CFD toolbox OpenFOAM [1]}, using second-order discretization schemes in both time and space.
<FIGURE>